OncoSec Medical has dosed the first patient in an investigator-initiated Phase II trial, OMS-104, of Tavo (tavokinogene telseplasmid), in combination with Opdivo (nivolumab) as neoadjuvant therapy before surgery in patients with operable, locally, or regionally advanced melanoma.

Tavo is intratumoral DNA plasmid-based interleukin-12 (IL-12) therapy given with the help of the company’s gene delivery platform, while Opdivo is an anti-PD-1 checkpoint inhibitor.

The open-label, single-arm study will analyse intratumoral Tavo delivered by gene electrotransfer, or short electric pulses, plus nivolumab as neoadjuvant therapy in patients with operable locally-regionally advanced melanoma.

It will enrol 33 patients and will have a neoadjuvant phase, a surgical phase, and an adjuvant phase.

Pathological complete response based on the number of subjects with no viable tumour on histologic assessment at definitive surgery after 12 weeks of neoadjuvant period will form the trial’s primary endpoint.

OncoSec president and CEO Daniel O’Connor said: “Tavo delivers DNA plasmid-based IL-12 directly into the tumour using gene electrotransfer, which demonstrably enhances the immunogenicity of the treated tumours to yield productive ‘in situ’ vaccines.

“This principle has yielded striking results in post-PD-1 patients and is likely relevant in this earlier clinical setting. We look forward to exploring the utility of TAVO as a potential neoadjuvant therapy in a variety of solid tumour settings for patients in need of more effective treatment options.”

In KEYNOTE-695 registration directed Phase II clinical trial, Tavo plus Keytruda (pembrolizumab) boosted overall response rate and partial tumour responses in patients with anti-PD-1 checkpoint-refractory metastatic melanoma.

Last January, OncoSec Medical secured a multi-year ClinSite licence from clinical development analytics products and services provider Phesi.